


Wave Function

by Lamachine



Series: Quantum Mechanics [2]
Category: Angel: the Series, Person of Interest (TV)
Genre: F/F, PWP, Threesome - F/F/F
Language: English
Status: Completed
Published: 2014-11-20
Updated: 2014-11-20
Packaged: 2018-02-26 09:32:32
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,190
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/2647034
Author URL: https://archiveofourown.org/users/Lamachine/pseuds/Lamachine
Summary: <blockquote class="userstuff">
              <p>
  <em>“Every system has one,” Fred murmured, closing her eyes. “The more complex the particles, the more complex the equation,” she continued before she yawned, so very tired. Against her, Root’s bare skin was incredibly hot and still had a thin layer of sweat, and Fred smirked as she thought of how it had gotten there. “But there’s always an equation to write.”</em>
</p>
            </blockquote>





	Wave Function

Fred didn’t know how it had happened exactly, but without her noticing, it had become a thing. Every time Sam or Root had a mission on the West Coast – missions she knew nothing about, apart from the injuries and scars that appeared on them both every other month – they always ended up at the Hyperion. Usually, one arrived before the other, but sometimes they knocked on Fred’s bedroom door together, an enormous grin on Root’s face, an annoyed frown on Sam’s, and no matter the day she was having, Fred could never find it in herself to throw them out.

 

 _Strays_ , she named them sometimes, although never aloud.

 

The night had just started to fall, yet already Fred was exhausted. There was a new cut on Sam’s stomach, not the graze of a bullet, but the fine thin line of a blade, and it made her want to stay close to her, to keep an eye on her even though the danger had long passed. Root hadn’t commented on it, really. Earlier, she had encircled Fred in her arms while she unbuttoned Fred’s pants, and whispered “she can handle herself” in the crook of her neck. After that, Fred’s bedroom had turned into a mess of heated limbs, and she couldn’t quite recall the details of how they had ended up the three of them, naked and lazy on her bed, with Root’s hand running in her hair while Fred rested on her shoulder. In front of them both, Sam lied down with one arm behind her head, half asleep.

 

Fred didn’t know how it happened, every time; how they just ended up like this, silent and warm, strangely at peace.

 

“Root?” she muttered, almost careful not to wake Sam, although she knew that Sam wasn’t truly sleeping yet, and that her trained ears always picked up everything she said. “Do you know about wave functions?”

 

Just like every other time she talked about physics, Fred noticed the slightest peek of interest in Sam. Behind her, Root only hummed, her fingers still running between Fred’s curls.

 

“Every system has one,” Fred murmured, closing her eyes. “The more complex the particles, the more complex the equation,” she continued before she yawned, so very tired. Against her, Root’s bare skin was incredibly hot and still had a thin layer of sweat, and Fred smirked as she thought of how it had gotten there. “But there’s always an equation to write.”

 

Root leaned down to bite her earlobe gently. “Is there?” she encouraged, and Fred recognised that low voice, that sultry tone that came before all that teasing Root loved so much. She shivered and Root’s arms wrapped around her, keeping her warm.

 

Sam opened her eyes them, looking at them both with a playful eye. She rarely had that look these days, Fred thought; this new Sam was grumpier than her younger self, more serious, too. But on some nights, when she was tired enough, Sam softened between Fred’s sheets, melting into Root and her.

 

“There is,” Fred turned around to face Root, finding her face only inches apart. She smiled; “no matter how complex.”

 

She pushed a curl of Root’s hair behind her right ear, running a finger down the skin gently, just above the Cochlear implant. It was something that Fred was curious about, that implant; she didn’t know how Root had ended up deaf in that ear, it simply wasn’t something she shared. Fred never insisted, but sometimes she invented stories about it, impossible tales in which Root always came out a hero, often saving Sam, and it made her feel a bit less anxious when she didn’t hear from them both for a while.

 

“It’s not really something you can measure,” Root warned, moving fast enough to grab Fred’s wrist and bring her hand closer. Root kissed her palm before she dragged Fred’s fingers down her throat, and all the way to her breast.

 

Fred repressed a small noise of surprise before she leaned into the touch, pressing hard against Root’s chest and noticing the flash of arousal appearing there. She spared a glance towards Sam, who hadn’t moved apart from one hand that had come to rest on her thigh. Fred swallowed hard, calculating the implications as she returned her attention to Root.

 

“Maybe not measure exactly, no, but something I can qualify,” Fred insisted, thoughts blurring as Root bit Fred’s lower lip.

 

Root’s fingers had started raking up Fred’s back, leaving pale lines to turn red in her wake; they weren’t as angry as the ones she drew on Sam and Fred had worried, at first, that Root was treating her differently, as if Fred wouldn’t be able to take it. Now, she understood that Root saw things in another light; she could take one look at Fred and know exactly what Fred needed in that moment, and if sometimes it was annoying, it was also very rewarding in other ways.

 

“If I understood the system better,” Fred added before Root’s mouth settled in the crook of her neck, sucking hard. She felt a moan growing in the back of her throat, but it turned into a quiet hum spreading through her chest, and she heard a shift in Sam’s breathing.

 

A glance to the side confirmed her hypothesis, as she noticed the small movement of Sam’s fingers between Sam’s legs. Fred bit her own lip then, the exhaustion lifting from her traits as Root placed a trail of warm kisses along her jawbone.

 

“Well, what would you need to create your equation?” Root asked, although her voice sounded more teasing than helpful.

 

Fred licked her lips in anticipation, and when Root pulled apart instead of kissing her, Fred fisted her hair and tugged her close, crashing their lips together. As it usually did, Root’s tongue darted forward, warm tip insistent until Fred allowed her in. When she parted her lips Root shifted on the bed, kneeling beside her instead of sitting, and Fred gasped against her.

 

“Well, go on,” Sam groaned from further on the bed, but the rough sound of her voice did nothing to hide her arousal. Fred smirked, eyes meeting with Root’s, who looked smug as always.

 

“The wave function is supposed to define the quantum state of a system in isolation,” Fred recited, almost as if reading a text book.

 

Sam grunted; “door’s closed,” and Root spared her a look.

 

“If you’re going to participate, you’ll have to do more than that, Shaw,” she criticised, but Sam only groaned, and continued to touch herself slowly, defiant eyes staring back into Root’s.

 

Fred let out a small laugh, cupping Root’s cheek and turning her attention towards her instead. “Let’s limit the momentum space to the bed for now,” she whispered, her breath running shivers down Root’s throat before she bit Root’s lower lip. Root’s fingernails dug in Fred’s sides just over her ribs, a quiet whimper leaving her mouth.

 

“Did I hurt you?” Fred asked when she pulled apart, worry nested in her gut. With Sam, she was bolder and less hesitant; with Root, she never knew where to stand, but she figured it was something that Root loved, that ambivalence towards her.

 

“Not nearly enough,” Root protested hungrily, and Sam laughed. “What?” Root asked her, suddenly annoyed.

 

Sam shook her head and rolled her eyes. “Nothing.”

 

Fred watched them both, amused. “See? This is something,” she reached for Sam’s calf with one hand, kneading the muscle while her other fingers ran down Root’s neck, teasing the skin until she flinched. “I could measure. The wave between you two,” she dug fingernails in both of their warm skin and revelled in the quiet hisses it pulled out of Root and Sam. “How much you pull,” she tugged on Sam’s ankle and felt the shift on the mattress as she moved to sit beside Fred, “how much you push.”

 

Root’s eyes were gleaming as Fred turned to face her, her hand tracing up Root’s thigh and finding her just as warm and wet as she had left her half an hour before. She felt Sam pressing herself against her back, her strong arms encircling Fred’s frail body and Fred leaned on her slightly, her fingers still teasing Root as she continued, “how you gravitate around each other.”

 

There wasn’t jealousy there, Fred realised as Root grinded on her hand, her fingers coming to wrap around Fred’s nape, holding onto her like she was the centre of everything. Behind her, Sam bit down her shoulder lightly and Fred hissed quietly, losing the trail of her thoughts.

 

“The degree of freedom,” Root whispered, licking her lips absently and Fred swallowed hard at the sight of Root’s hair still dishevelled from before, her eyes closed as she shifted closer, urging Fred on. “Am I doing this right?” she whispered in Fred’s ear just as Sam’s hand, trekking down her stomach, finally reached her labia. Fred gasped before she nodded, not trusting herself to speak.

 

Sam’s fingers teased nipples and clit alike, and Fred felt her lungs burning up as her breathing turned scarce. She focused on Root’s rhythm, the slow swaying of her hips, until she couldn’t bear it anymore. Fred’s fingers moved inside her unhurriedly, taking her time to pull out the reaction she wanted; Root opened her eyes and whispered her name, and Fred’s concentrated traits turned into a smirk.

 

When Sam did the same, her digits slipping inside Fred almost stealthily, Fred moaned against Root’s lips, only slightly annoyed to find them curling up, smug.

 

“You were saying?” Sam taunted her from behind, her raspy voice sending a wave of arousal in Fred, and that she also felt crashing in Root.

 

Sam’s second hand disappeared then, only to be replaced by Root’s lips on Fred’s breast, biting the nipple lightly before she soothed the pain with her tongue. From the awkward pressure of a limb against her spine, Fred deduced Sam was touching herself again and she tugged on Root’s hair, urging her on.

 

“There’s, the spin,” Fred whispered with difficulty, the words barely formed in her mind. Root laughed against her chest, head rising until she could stare into Fred’s eyes again.

 

“Yes, the spin,” she agreed, one hand digging nails into Fred’s nape as the other kneaded her breast, “how would you calculate the spin, Fred?”

 

Root was taunting her, Fred knew as much, but from Sam’s heat behind her and Root’s arousal wrapped around her fingers she found she had lost the equation. She tried to retrace her steps, the notions she had mentioned before, and swallowed hard.

 

“It’s like I said,” Fred grinded against Sam’s hand, fingers still fisting Root’s hair so tightly she was sure to be hurting her, but Root wasn’t protesting. “The push and pull,” she repeated, hissing when Root’s fingers twisted a nipple.

 

“You mean, the magnetic moment,” Root continued, voice almost composed despite how she desperately moved against Fred’s hand. She stared into Sam’s eyes, looking at her from above Fred’s shoulder, as she went on, “when _attraction_ wins over resistance.”

 

Behind Fred, Sam groaned in annoyance at Root’s corny line, and Fred chuckled. It brought a smile to Root’s lips, and diffused heat in Fred’s chest; like she had done something right. Like she had found another number to add to her equation.

 

“What’s the matter, Shaw?” Root mocked, slowing down. “I thought you liked _physics_.”

 

Sam grunted again; “would you just shut up?”

 

They continued to move in silence for a moment, right until Root picked up a more rapid rhythm. She pressed her forehead against Fred’s as she muttered a short, “Shaw?”

 

Fred felt the shift behind her, Sam’s arm leaving the line of Fred’s spine to reach Root’s hips, fingernails sinking into the skin almost angrily. Root gasped in approval, pressing herself closer to Fred, making it almost impossible to breathe. Root leaned over Fred’s shoulder awkwardly and Fred closed her eyes, listening to the small, wet noise of Sam’s lips on Root’s.

 

In this position it was barely possible for Fred to continue moving within Root, and so Root pulled apart with an apologetic smile that still looked more like smug than anything else. Root came only moments later, with Sam’s fingers bruising her skin and Fred’s digits trembling inside her, and Fred followed only seconds later, a whispered “Sam” crossing her lips before Root’s tongue slipped inside her mouth, swallowing the name hungrily.

 

As Root kissed her Fred felt Sam’s hand leaving her, which seemed to remind her that she hadn’t pulled out of Root yet. She moved her hand slowly and Root moaned softly against her, the sound so intimate that Fred wished her breathing wasn’t so scarce and her heart wouldn’t beat so fast, so that she could’ve heard it better.

 

Behind her, Sam removed Fred’s hair from her shoulder, biting at the crook of her neck. Fred smiled when her eyes met Root’s.

 

“You know, the thing about waves,” Root started, smirking, and Fred bit her lip before she turned around, staring at Sam eagerly, and completing Root’s thought; “is that they never really stop.”


End file.
